This invention relates generally to semiconductor production processes, and more specifically to methods and apparatus for cleaning plasma process systems.
High density plasma chambers are used in a number of semiconductor processing steps including silicon-dioxide deposition processes and high energy etching processes. Whether used for deposition or etching, the sides of the plasma chamber eventually become coated with the material being deposited or etched. Subsequently, the material on the chamber sides may loosen from the sides and form particulates that present a contamination concern for the semiconductors being processed. As such, the high-density plasma chambers must be periodically cleaned.
High density plasma chambers are frequently cleaned by introducing a cleaning gas, such as disassociated fluorine, into the plasma chamber. The cleaning process may be augmented by striking a plasma in the plasma chamber during cleaning. However, even when a plasma is used during cleaning, the cleaning efficiency for surfaces downstream of the plasma is significantly less than for the surfaces in the vicinity of the plasma. As a result, longer cleaning cycles are required to fully clean the chamber surfaces. Therefore, a method of cleaning a plasma chamber that increases the cleaning efficiency for areas downstream of the plasma zone is desirable for semiconductor processing systems.
A method of cleaning a high density plasma system is disclosed, the method comprising the steps of providing a high density plasma system comprising a process chamber having a wafer chuck disposed therein, a flow channel providing fluid communication between the process chamber and a high vacuum pump such that the process chamber and the flow channel are connected to form a continuous inner surface, wherein the flow channel comprises a valve disposed between the process chamber and the high vacuum pump; introducing a hot gas into the system between the wafer and the valve such that the inner surface between the wafer and the valve is heated; and introducing a cleaning gas into the system such that deposits located on the heated inner surface are substantially removed.
In accordance with one aspect of the invention, a method of cleaning a high density plasma system is disclosed. The method comprising the steps of: providing a high density plasma system comprising a process chamber having a wafer chuck disposed therein, a flow channel providing fluid communication between the process chamber and a high vacuum pump such that the process chamber and the flow channel are connected to form a continuous inner surface, wherein the flow channel comprises a valve disposed between the process chamber and the high vacuum pump; introducing a hot gas into the system between the wafer and the valve such that the inner surface between the wafer and the valve is heated; and introducing a cleaning gas into the system such that deposits located on the heated inner surface are substantially removed, wherein the valve is closed.
In accordance with another aspect of the invention a method of cleaning a high density plasma system is disclosed, the method comprising the steps of: providing a high density plasma system comprising a process chamber having a wafer chuck disposed therein, a flow channel providing fluid communication between the process chamber and a high vacuum pump such that the process chamber and the flow channel are connected to form a continuous inner surface, the process chamber being disposed upstream of the high vacuum pump, wherein the flow channel comprises a valve disposed between the process chamber and the high vacuum pump; closing the valve such that fluid communication between the process chamber and the high vacuum pump is interrupted; introducing a hot gas into the system between the wafer and the valve such that the inner surface between the wafer and the valve is heated; introducing a cleaning gas into the system such that deposits located on the heated inner surface are substantially removed; introducing a cleaning gas into the system downstream of the closed valve such that deposits located on the high vacuum pump are substantially removed.
In accordance with yet another aspect of the invention a method of cleaning a high density plasma system is disclosed, the method comprising the steps of: providing a high density plasma system comprising a process chamber having a wafer chuck disposed therein, a flow channel providing fluid communication between the process chamber and a high vacuum pump such that the process chamber and the flow channel are connected to form a continuous inner surface, the process chamber being disposed upstream of the high vacuum pump, wherein the flow channel comprises a valve disposed between the process chamber and the high vacuum pump; setting the valve in an open position such that fluid communication between the process chamber and the high vacuum pump is permitted; introducing a hot gas into the system between the wafer and the valve such that the inner surface between the wafer and the valve is heated; and introducing a cleaning gas into the system such that deposits located on the heated inner surface are substantially removed and deposits located on the high vacuum pump are substantially removed.
In yet another aspect of the invention a method of cleaning a high density plasma system is disclosed, the method comprising the steps of providing a high density plasma system comprising a process chamber having a wafer chuck disposed therein, a flow channel providing fluid communication between the process chamber and a high vacuum pump such that the process chamber and the flow channel are connected to form a continuous inner surface, the process chamber being disposed upstream of the high vacuum pump, wherein the flow channel comprises a gate valve disposed between the process chamber and the high vacuum pump, wherein the gate valve has a valve blade comprising at least one orifice having an electromechanical valve attached to the blade upstream of and positioned over the orifice, the electromechanical valve having an open position permitting fluid communication through the orifice and a closed position preventing fluid communication through the orifice; closing the gate valve such that the valve blade interrupts fluid communication between the process chamber and the high vacuum pump; introducing a hot gas into the system between the wafer and the gate valve such that the inner surface between the wafer and the gate valve is heated; introducing a cleaning gas into the system such that deposits located on the heated inner surface are substantially removed; positioning the electromechanical valve into an open position such that the cleaning gas is introduced into the system downstream of the closed gate valve such that deposits located on the high vacuum pump are substantially removed.
An apparatus is disclosed for processing substrates comprising a process chamber having a wafer chuck disposed therein; a high vacuum pump; a flow channel providing fluid communication between the process chamber and the high vacuum pump such that the process chamber and the flow channel are connected to form a continuous inner surface, the process chamber being disposed upstream of the high vacuum pump, wherein the flow channel comprises a valve disposed between the process chamber and the high vacuum pump; a first inlet between the wafer and the valve, the first inlet connected to a source of a hot gas; and a second inlet connected to a source of a cleaning gas.
An apparatus is disclosed for processing substrates, comprising a process chamber having a wafer chuck disposed therein; a high vacuum pump; a flow channel providing fluid communication between the process chamber and the high vacuum pump such that the process chamber and the flow channel are connected to form a continuous inner surface, the process chamber being disposed upstream of the high vacuum pump, wherein the flow channel comprises a valve disposed between the process chamber and the high vacuum pump; a first inlet between the wafer and the valve, the first inlet connected to a source of a hot gas; a second inlet connected to a source of a cleaning gas; and a third inlet downstream of the valve, the third inlet connected to a source of a cleaning gas.
An apparatus is disclosed for processing substrates, comprising a process chamber having a wafer chuck disposed therein; a high vacuum pump; a flow channel providing fluid communication between the process chamber and the high vacuum pump such that the process chamber and the flow channel are connected to form a continuous inner surface, the process chamber being disposed upstream of the high vacuum pump, a gate valve disposed in the flow channel between the process chamber and the high vacuum pump wherein the gate valve has a valve blade comprising at least one orifice having an electromechanical valve movably attached to the blade upstream of and positioned over the orifice, the electromechanical valve having an open position permitting fluid communication through the orifice and a closed position preventing fluid communication through the orifice, a first inlet between the wafer and the gate valve, the inlet connected to a source of a hot gas; and a second inlet connected to a source of a cleaning gas.